One of the jobs that I’ve not looked forward to is the fuel flow test. Not because it’s difficult or complicated but more that it seems dangerous. It involves taking a feed off of the carb line and running a long pipe away from the engine and prop. Several timed measurements take place using the electric pump on it’s own with the engine stopped, one with the engine running at full bore using just the mechanical pump and one with the mechanical and electric pumps working together. The aircraft has to be choked and Ian offered to do the work outside the cockpit. We used radios to signal the start and stop of each engine run.